ASIC bumping

Gold stud bumps deposition was successfully tried with Hybrid SA company and very good reproducibility of bump deposition and without a single defect detected on many samples. Therefore the ASICs will have Au stud bumps (about 60 microns diameter and 45 microns height, before possible coining) on each bonding pad and the connection to the FPC will be via flip-chip to matching bonding pads (ENIG), using Araldite 2011 to bond the assembly mechanically.

Image 1
Gold stud bump from NMP-FCBG
Image 2
Coined Au stud with 200g
Image 3
Chip's edge with Au stud bumps

Coining technique was tested and adequate force of 200 g/bump looks reasonable.

Here’s a link to the PDFinstead.